NTP v3 server, v4 client can't synch

NTP v3 server, v4 client can't synch

Post by David J Ta » Thu, 10 Sep 2009 14:43:08


Get the host machine synced with NTP, and let VMware handle the timing for
the client OS. There is a VMware paper on time syncing IIRC. The
timekeeping won't be wonderful - perhaps to within a second or two?


NTP v3 server, v4 client can't synch

Post by Unru » Fri, 11 Sep 2009 02:53:51

Romain Kang From: < XXXX@XXXXX.COM > writes:

I am sorry, but that is an poor place to be using ntp. A virtual machine
has really horrible timing characteristics and the ability to discipline
its clock is almost non-existent. What you need to do is to discipline
the server clock which has access to the hardware to discipline its
clock, and get your virtual machine to get its time from there.

A VM is NOT the same as a real computer, and for timing it is useless.

No. The problem is NOT with network delays. The problem is with the
clock. It is useless. This is like asking how in the world one can make
a $1 Mickey Mouse windup watch give accurate time. It cannot. The VM
clock is probably drifting out of the range of ntp's ability to fix it.

You might try chrony ( far faster at converging) if you are running
linux or BSD, but I would not hold out much hope there either. You are
beating your head against a brick wall.

Get a real computer.
Get the underlying OS to discipline its clock and have your virtual
machine get its time from there.


NTP v3 server, v4 client can't synch

Post by David J Ta » Fri, 11 Sep 2009 03:43:49


My immediate reaction is that this is fundamentally flawed (and I would
probably put it less politely were we face-to-face!).